Geochemical Fractions of the Agricultural Soils of Southern Poland and the Assessment of the Potentially Harmful Element Mobility

Mazur-Kajta Mazur-Kajta,Baran Baran,Czech Czech,Gruszecka-Kosowska Gruszecka-Kosowska

doi:10.3390/min9110674

Abstract

Surface samples (0–25 cm each) of agricultural soils were investigated in five Regions (voivodeships) of southern Poland. The mean Potentially Harmful Element (PHE) pseudototal content ranges were as follows (mg/kg): As 5.19–10.9, Cd 0.34–1.56, Co 1.92–6.70, Cr 9.05–25.7, Cu 8.74–69.4, Hg 0.001–0.08, Ni 3.93–19.9, Pb 20.3–183, Sb 0.80–1.42, Tl 0.04–0.17, and Zn 61.3–422. The PHE availability depended on pH, the organic carbon (Corg) content, and the pseudototal PHE content in soils. Exchangeable and acid soluble PHE contents (BCRF1) determined in the Community Bureau of Reference (BCR) three-step sequential extraction procedure decreased in this order: Cd > Zn > Co > Ni = Sb > Cu > Tl > As > Cr = Pb. Actually available PHE contents in pore water (0.01 mol/dm3 CaCl2) ranged as follows: Cd 0.81–17%, Cr 0–0.25%, Cu 0.01–2.31%, Ni 0.16–2%, Pb 0.2–0.49%, and Zn 0.25–2.12%. The potential soluble total content of PHEs in pore water (0.05 mol/dm3 Na2EDTA) ranged as follows: Cd 27–91%, Cr 0.7–7.1%, Cu 6.7–98%, Ni 3.6–41%, Pb 15–41%, and Zn 3–34%. The mobility factor (MF) values indicated Cd (31.6%) and Zn (21.0%) as the most mobile elements in soil. Other PHEs followed the order of Co > Ni > Tl > As > Sb > Cu > Cr > Pb, with the MF values <10%. The risk assessment code (RAC) values revealed a very high ecological risk of Cd and Zn in the Podkarpackie Region and a high ecological risk of Cd in the Regions of Opolskie, Śląskie, Małopolskie, and Podkarpackie, and the same of Zn in the Opolskie and Śląskie. The modified risk assessment code (mRAC) index pointed a very high potential of adverse effects in soils in the Podkarpackie and a medium potential in the Opolskie, Śląskie, Małopolskie, and Świętokrzyskie. The potential adverse effect risk, described by the individual contamination factor (ICF) factor, was the following in the Regions, in the decreasing order: Cd > Pb > Sb > Zn > Co > Cu > Ni > Tl > As > Cr, and the same as described by the global contamination factor (GCF) values: Opolskie > Podkarpackie > Świętokrzyskie > Śląskie > Małopolskie.

Highlights

Harmful elements (PHEs) can pose a threat to living organisms due to their toxic and carcinogenic effects [1]
Basic statistical Potentially harmful elements (PHEs) characteristics in the investigated regions is given on Figure 2
The results indicated that the mobility of PHEs generally depended on the pH and Corg contents, while the mobility of Cu and Zn depended on the pseudototal contents of those elements in soils

Summary

Introduction

Harmful elements (PHEs) can pose a threat to living organisms due to their toxic and carcinogenic effects [1]. They are still considered to be some of the most hazardous groups of inorganic contaminants in the environment. Thirteen trace metals and metalloids are recognised to be priority. Those elements are generally divided into macro- and microelements [3]. E.g., Pb and Cd, are considered to be harmful to humans, even in low concentrations [4]

Methods

Results

Conclusion